1. Field
The following description relates to display platform technology that visualizes a 3D stereoscopic image, and more particularly, to technology that provides digital content service utilizing the display platform technology.
2. Description of the Related Art
Three-dimensional (3D) stereoscopic image technology which is being popularized in movies, television (TV), and the like generally uses a binocular disparity effect, which refers to a difference in image location of a 3D object seen by the left and right eyes of an observer, among various human factors which contribute to a 3D stereoscopic effect. However, 3D stereoscopic image presentation technology based on the binocular disparity effect has limitations which are fundamentally difficult to overcome when representing a natural 3D stereoscopic effect. For example, in the above-described technology, images having virtual depth, which are formed in front of and behind an image output surface (for example, LCD or screen) at a fixed distance, are presented to users by outputting binocular disparity information on the image output surface, and therefore an accommodation-convergence mismatch problem due to an increase in the stereoscopic effect is created, which significantly fatigues the human visual motion and cognitive structure.
The accommodation-convergence mismatch problem is a phenomenon in which a convergence distance and a focal distance do not match. Convergence refers to a simultaneous inward movement of eyes toward each other with respect to a target object, and a user focuses on the image output surface while convergence is formed in front of and behind the image output surface, so that the convergence distance and the focal distance do not match. Commercial 3D stereoscopic imaging devices (for example, 3D TV, 3D cinema, autostereoscopic 3D display, HMD, EGD, and the like), excluding a pure holographic output device for recording and restoring an image using a laser light source, are all stereoscopic image output devices based on binocular disparity, and thereby have the above-described problem. Accordingly, existing systems try to reduce adverse effects by changing a viewing environment such as content, viewing time limit, viewing position limit, and the like. However, as this fundamental problem has not been resolved, social awareness about side effects is increasing, and recently, interest within the industrial and research worlds has increased, as evidenced by the establishment of organizations such as the Human Factor Research Institute and Forums concerning 3D stereoscopic images.
Interactive hologram display technology, which is 3D image presentation technology presented in content such as movies, is ideal display technology that is perfectly adapted to human stereoscopic visual recognition characteristics. However, it is difficult to obtain high visual quality and to realize interactive hologram display technology, in future science fiction films for example, at the current level of technology, in which a virtual hologram effect is achieved utilizing a reflective optical structure, only still images are represented, etc. This may lead to misunderstanding about 3D stereoscopic image commercialization technology and disappointment about current technology among average consumers.
3D movies and 3D TV attract public interest, and thus commercials employ high-level 3D stereoscopic effects such as a ball coming out of a screen and rolling right by a viewer. Such phenomena may be interpreted as an expression of the desires of manufactures and users to enjoy realistic stereoscopic content through 3D stereoscopic imagery. However, in the above-described technology based on the binocular disparity effect, when a target object to be observed strays from a range of a view volume defined between an image output screen of a display device and user's eyes, or when the target object is represented by an excessive stereoscopic effect, human factor issues (for example, eye pain, dizziness, and the like) occur, and thus the technology is actually only being used for virtual commercial images.